using earmuffs on outboard

cool change

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Hi all. I wanted to know is using earmuffs on a outboard good for the engine.. I am always afraid that the motor is not getting enough water and could cause serious damage .. would love to know ur opinion. thanks
 

seasick

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cool change said:
Hi all. I wanted to know is using earmuffs on a outboard good for the engine.. I am always afraid that the motor is not getting enough water and could cause serious damage .. would love to know ur opinion. thanks
It depends on a lot of things: Water pressure at the muffs, water volume, single vs dual muffs, motor model, HP etc.
I will say that in general most outboards can be started and run on muffs but 'run' is subjective. No all out revs etc and if the motor has a telltale stream it usually should be 'peeing' although that may or may not happen without the motor started.
If the muffs cover the inlet ports or grills, then water will get to the pump. On some motors, you cant cover the inlets with muffs. Some motors like my Yami 150 have two inlets, one on each side, but will run fine on a single muff (the second cup just plugs the inlet)
Of course if you have a temp gauge it is easy to see if there is a problem. Otherwise you will have to relay on the temp alarm if there is a problem.
Note that a motor that normally is happy on muffs may not be if the water pump is not up to par.
 

Denko

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seasick said:
Note that a motor that normally is happy on muffs may not be if the water pump is not up to par.
Great point!
 

DennisG01

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OK, so assuming you have decent flow from the hose (Seasick mentioned many good points), you will be TOTALLY fine. Turn the hose on full bore and have at it. The reason I asked about it being a 2-stroke is that often times, 2-strokes will run a bit wild (slightly elevated RPM, possibly a little up/down RPM, but nothing to be concerned about). In other words, just don't expect it to run as smoothly as it does in water. The reason is that it doesn't have the back pressure of the water on the exhaust. If you happen to have a big tub that fits around it, you could use that. But a hose is perfectly adequate.
 

cool change

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thank u so much dennis .. i always look forward to ur replys and knowlege
 

seasick

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DennisG01 said:
cool change said:
thank u so much dennis .. i always look forward to ur replys and knowlege

You're welcome. I'm glad my ramblings are sometimes helpful!
Dennis
The point about back pressure is a good one buy I have a funny story about that. Last fall on the boat'slast day in the water and when getting ready to haul for the winter, my 150SX started surging at idle. Revs up and down. If I increased the revs it didn't surge. I couldn't look at it since I was all set to haul so I had to think about possible causes all winter. Well, 2 days ago , started the motor on muffs as I do each new season to burn off the winter treatments and prior to replacing the usual filters, plugs etc. I expected the motor to start surging but it didn't. Not only that it idlesd very nicely on the muffs. What the heck:) She wont go into the water for a few days ( It is really windy in NY this week) and I also have a little slip prep to finish. So what's the story with the surging? I don't know. These things usually don't go away on their own. It was colder when I hauled and that could be a factor and I had just added Stabil. Let's see how it goes. I will let you know if I end up calling Sea Tow:)
Seasick
 

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That's definitely a head scratcher, Seasick, as there's many possibilities. And, you're right, things don't usually fix themselves. The one thing that stands out, to me, is that you said "just added stabil". Now, from that statement alone, it sounds like you may not always use it or you added a healthy extra dose of it. If that's the case, I might think that something could have been slightly fouled. The extra dose of stabil sitting on it all Winter ate away at the fouling and it burned off while you did your Spring pre-run. I've had experience with heavy doses of stabil doing just that with small engines that were running a little off. At least... that's the only variable that I see from what you wrote. I guess just give a good run and see what happens.
 

wlewis

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I tried an earmuff on my F250 while running the motor and it overheated after about 3 or 4 minutes. When researching the issue on Yamaha website, they recommend when running the motor, using 2 hoses, one on the earmuff and the second on the upper hose intake. For flushing without running motor, a single hose is ok. Since I previously had always run my 2 stroke motors while flushing, and all was ok, I assume 4 strokes must require increased water flow.
 

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I use a stock tank that can be found at any farm supply store. When the tank is full, I keep the garden hose running so there always cool water flowing. With this method, you can run your motor all day without an overheat.
 

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Just adding my nickle's worth, though not as detailed as Seasick, and Dennis. My first winterizing after purchasing the boat, I was told I needed to replace the water pump because it was partially melted. When I asked what could cause it to melt, he answered "running the motor on muffs". I personally like the idea of running it in a big tank.
 

seasick

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DennisG01 said:
That's definitely a head scratcher, Seasick, as there's many possibilities. And, you're right, things don't usually fix themselves. The one thing that stands out, to me, is that you said "just added stabil". Now, from that statement alone, it sounds like you may not always use it or you added a healthy extra dose of it. If that's the case, I might think that something could have been slightly fouled. The extra dose of stabil sitting on it all Winter ate away at the fouling and it burned off while you did your Spring pre-run. I've had experience with heavy doses of stabil doing just that with small engines that were running a little off. At least... that's the only variable that I see from what you wrote. I guess just give a good run and see what happens.

That was first though, that the Stabil which I just added may have fouled the O2 sensor and that caused the air/fuel mixture to go too rich. If the problem reoccurred when i just started it for the new season, my first step would be to clean the O2 sensor. the next possible cause could be a bad low pressure pump but as mentioned, things were just too coincidental with the adding of a healthy dose of Stabil. I did post and asked if anyone had a similar problem after adding Satbil but all responses were negative.
Well if it was the Stabil, in theory the problem may not return. That would be an exception to the adage that boat problems never go away on their own:)
 

seasick

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Bumpye said:
Just adding my nickle's worth, though not as detailed as Seasick, and Dennis. My first winterizing after purchasing the boat, I was told I needed to replace the water pump because it was partially melted. When I asked what could cause it to melt, he answered "running the motor on muffs". I personally like the idea of running it in a big tank.
Running the pump dry can overheat the impeller but more often than not the impeller got damaged by something else. Two common things are sand/crap getting sucked into the pump and running dry as can happen when you get something like a plastic bag blocking the inlets. The key issue with muffs is the water flow volume which is directly related to water pressure and hose size and length.
When muffs are put on and the water is turned on with the motor off, water should after a few seconds, flow out of all the places it normally does and with a decent flow rate. That should continue after the motor is started. If the 'overflow' stops or reduces significantly when the motor is started, then there is not enough water volume.
I know for a fact that you can run those motors on the flush port with a hose if you have enough water pressure and not damage the impeller
 

DennisG01

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Bumpye said:
Just adding my nickle's worth, though not as detailed as Seasick, and Dennis. My first winterizing after purchasing the boat, I was told I needed to replace the water pump because it was partially melted. When I asked what could cause it to melt, he answered "running the motor on muffs". I personally like the idea of running it in a big tank.

Me thinks you were giving a bit of a "line" there. Unless the water hose got kinked or the muffs slipped off (I often either bungee it on, or use a style that is mechanically secured), there is no way that an impeller is going to melt. It has "first dibs" on the full supply of water, you know? Whether or not the powerhead on a 4-stroke Yammie needs extra flow, or not, I don't know. But I can tell you that I run everything from 4cylinder sterndrives to big block sterndrives, multiple sizes 2-strokes, even a few 4-stroke Merc OB's.... never with any issue... not even an overheat. I'm not discounting any of your experiences or thoughts - just that there is most likely more to the story than the mechanic was relaying to you.
 

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seasick said:
DennisG01 said:
That was first though, that the Stabil which I just added may have fouled the O2 sensor and that caused the air/fuel mixture to go too rich. If the problem reoccurred when i just started it for the new season, my first step would be to clean the O2 sensor. the next possible cause could be a bad low pressure pump but as mentioned, things were just too coincidental with the adding of a healthy dose of Stabil. I did post and asked if anyone had a similar problem after adding Satbil but all responses were negative.
Well if it was the Stabil, in theory the problem may not return. That would be an exception to the adage that boat problems never go away on their own:)

I'm actually thinking more along the lines that possibly, being towards the end of the season, maybe the boat had been sitting a bit and allowed "gunk" (for lack of a better term) to gather somewhere. So that may be the reason that it was running rough - not so much the actual Stabil. Stabil actually will HELP to keep things cleaner, so I really can't imagine that it caused any harm. If you happen to not be running a stabilizer (or similar) on a regular basis, then that could lend more credence to my theory... which is just that, of course, a theory. :D
 

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I have been using muffs on my 4 stroke outboards for about 15 years 2 F150's and 1F200. never had an issue. I believe it is more about volume than pressure as the water pump brings it up to the block. I use a single (one sided) muff. I will say, I had an overheat on the water last year where a plastic bag wrapped around the intake. The Yamaha overheat alarm is very sensitive and goes off way ahead of any possible damage. Cheers, trapper
 

Bumpye

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So after reading all the other posts, I decided to hook up the muffs and start the engine before launching next week (hopefully). I have a 225 Yamaha with rectangular intakes. I purchased the muffs with square cups and attempted to cover the intakes. The problem is the intakes are located on the lower end where it starts to flare out to the bottom "bulge". The cups would not fit tightly on the intakes. I started the engine anyway, and the second it started, I shut it off. Just wanted to make sure it would start anyway. Are there other muffs available? I've only seen two available in the other shops...round or square cups.